JP2004228208A - Substrate for inspection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a resistance value from being increased between a substrate electrode on a wiring board and a terminal on a flexible board even if applied pressure for making the wiring board come close to the flexible board acts repeatedly, and to prevent adjacent probe terminals from being continuous each other even if the pitch of the probe terminals becomes small. <P>SOLUTION: The flexible board 22 is arranged between a semiconductor wafer 12 having an electrode 12a for inspection and the wiring board 21 having the substrate electrode 21c, and a probe terminal 22a is provided on the lower surface of the flexible board 22. On the upper surface of the flexible board 22, a first terminal 22b connected to the probe terminal 22a and a second terminal 22c connected to the first terminal 22b are provided. An insulating sheet member 23 is provided between the wiring board 31 and the flexible board 22. The insulating sheet member 23 is provided with a conductive material 23a which electrically connects the substrate electrode 21c on the wiring board 21 to the second terminal 22b, and a projection 23b which absorbs the step of the probe terminal 22a. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inspection substrate for collectively inspecting electrical characteristics of a plurality of semiconductor chips formed on a semiconductor wafer in a wafer state.
[0002]
[Prior art]
2. Description of the Related Art In recent years, remarkable progress has been made in miniaturization and cost reduction of electronic devices equipped with a semiconductor integrated circuit device (hereinafter, referred to as a semiconductor device). ing.
[0003]
Normally, a semiconductor device is supplied after a semiconductor chip and a lead frame are electrically connected to each other by bonding wires, and the semiconductor chip and the lead frame are sealed with resin or ceramics, and mounted on a printed circuit board. However, due to the demand for miniaturization of electronic devices, a method of directly mounting a semiconductor chip as cut out from a semiconductor wafer (hereinafter, this semiconductor chip is referred to as a bare chip) on a circuit board has been developed. In order to cope with this, it is desired to supply bare chips with guaranteed quality at a low price.
[0004]
In order to perform quality assurance on bare chips, it is necessary to inspect a plurality of semiconductor chips formed on a semiconductor wafer, such as burn-in, at the wafer level. However, since it takes a lot of time to perform the inspection for a plurality of semiconductor chips on a semiconductor wafer one by one or several times, it is not practical in terms of time and cost. Therefore, it is required that all the semiconductor chips on the semiconductor wafer be subjected to a test such as burn-in at the wafer level.
[0005]
In order to inspect a plurality of semiconductor chips collectively at a wafer level, a power supply voltage or a signal is simultaneously applied to inspection electrodes of a plurality of semiconductor chips formed on a semiconductor wafer, and the plurality of semiconductor chips are inspected. Need to work. For this purpose, it is necessary to prepare an inspection board having a very large number of probe terminals (usually several thousand or more). From the point of view of price and price.
[0006]
Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-231019, an inspection substrate capable of simultaneously contacting a plurality of probe terminals formed of bumps with a plurality of inspection electrodes of a plurality of semiconductor chips on a semiconductor wafer has been proposed. ing.
[0007]
Hereinafter, a conventional inspection substrate will be described with reference to a cross-sectional view of FIG.
[0008]
As shown in FIG. 3, a semiconductor wafer 12 on which a plurality of semiconductor chips are formed is held on a wafer tray 11, and a plurality of inspection electrodes 12a are formed on a main surface (upper surface) of the semiconductor wafer 12. Have been.
[0009]
A wiring board 51 is arranged above the semiconductor wafer 12, and a lower wiring 51a, an upper wiring 51b, and a substrate electrode 51c are formed on a surface (lower surface) of the wiring substrate 51 facing the main surface of the semiconductor wafer 12. The substrate electrode 51c is connected to the lower wiring 51a, and the substrate electrodes 51c are connected to each other by the upper wiring 51b.
[0010]
A flexible board 52 is arranged between the semiconductor wafer 12 and the wiring board 51 so as to be spaced from the wiring board 51. A plurality of probe terminals 52a formed of bumps are formed on a portion of the first main surface (lower surface) of the flexible substrate 52 that faces the semiconductor wafer 12 and faces the inspection electrode 12a. A plurality of terminals 52b, which are electrically connected to the corresponding probe terminals 52a, are provided on the second main surface (upper surface) of the flexible substrate 52 opposite to the wiring substrate 52 on the opposite side of each probe terminal 52a. Is formed.
[0011]
An elastic sheet member 53 made of, for example, rubber is disposed between the flexible board 52 and the wiring board 51. At a portion of the elastic sheet member 53 corresponding to the terminal 52b of the flexible board 52, a plurality of conductive particle rows (conductors) 53a connected in a chain in the thickness direction of the flexible board 52 are provided. The board electrode 51c of the wiring board 51 and the terminal 52b of the flexible board 52 are electrically connected. In this case, the portion of the elastic sheet member 53 where the conductive particle row 53a is provided protrudes toward the flexible substrate 52, and the protruding portion allows the probe terminal 52a of the flexible substrate 52 to be connected to the inspection electrode 12a of the semiconductor wafer 12. Therefore, even if the semiconductor wafer 12 has a stepped portion or warpage, a reliable contact between the probe terminal 52a and the inspection electrode 12a can be obtained over the entire surface of the semiconductor wafer 12. Can be secured.
[0012]
[Problems to be solved by the invention]
However, in the conventional test board, when a pressing force for bringing the wiring board 51 and the flexible board 52 close to each other repeatedly acts, a compressive force repeatedly acts on the protruding portion of the elastic sheet member 53. For this reason, the arrangement of the conductive particle rows 53a is disturbed, and the resistance value of the conductive particle rows 53a increases, so that the resistance value between the board electrode 51c of the wiring board 51 and the terminal 52b of the flexible board 52 increases. There is a problem of doing. According to an experiment conducted by the inventor of the present invention, it has been found that the resistance value of the conductive particle row 53a is significantly increased when the pressing force and the releasing operation are performed about 300 times.
[0013]
In addition, when the pitch of the test electrodes 12a and thus the pitch of the probe terminals 52 are reduced, the pitch of the protrusions of the elastic sheet member 53 is also reduced. For this reason, in the manufacturing process of the elastic sheet member 53, the conductive particle row 53a provided inside the protruding portion is electrically connected to the conductive particle row 53a provided inside the adjacent protruding portion. In addition, there is a problem that adjacent probe terminals 52 are electrically connected to each other.
[0014]
In view of the above, the present invention prevents the resistance value between the substrate electrode of the wiring substrate and the terminal of the flexible substrate from increasing even when the pressing force for causing the wiring substrate and the flexible substrate to approach each other repeatedly, An object of the present invention is to prevent adjacent probe terminals from conducting even if the pitch between the probe terminals is reduced.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, an inspection substrate according to the present invention applies a voltage to a plurality of inspection electrodes of a plurality of semiconductor chips formed on a semiconductor wafer, and changes the electrical characteristics of the plurality of semiconductor chips to a wafer. A wiring board having a plurality of substrate electrodes on a surface opposed to a main surface on which a plurality of testing electrodes are formed on a semiconductor wafer, for a testing substrate for collectively testing at a level; A first main surface facing the main surface of the semiconductor wafer and a second main surface facing the surface of the wiring substrate on which a plurality of substrate electrodes are formed, provided between the substrate and at a distance from the wiring substrate; A flexible substrate having a main surface, a plurality of probe terminals provided at portions of the first main surface of the flexible substrate facing the plurality of inspection electrodes, and a plurality of probe terminals provided on a second main surface of the flexible substrate. A plurality of first terminals provided at a portion facing the probe terminal and electrically connected to the facing probe terminal, and different from the plurality of first terminals on the second main surface of the flexible substrate. A plurality of second terminals provided at the site and electrically connected to the corresponding first terminals; and a plurality of substrate electrodes and a plurality of second terminals provided between the wiring substrate and the flexible substrate. A plurality of conductors for electrically connecting the corresponding substrate electrode and the second terminal among the plurality of terminals, and a plurality of conductors provided at portions opposed to the plurality of first terminals between the wiring board and the flexible substrate. And an elastic body.
[0016]
According to the inspection board of the present invention, since the elastic body for absorbing the step of the probe terminal and the conductor for electrically connecting the board electrode and the second terminal are provided separately, the wiring board and Even if the pressing force for causing these to approach the flexible board repeatedly acts, and the elastic body is deformed or its elastic force is deteriorated, the gap between the board electrode of the wiring board and the second terminal of the flexible board is maintained. Does not increase. In addition, since the second terminal electrically connected to the substrate electrode is provided at a position different from the first terminal provided at a portion facing the probe terminal, the pitch of the second terminal is set to the first terminal. Since the pitch of the first terminals can be made larger than the pitch of the first terminals, it is possible to prevent adjacent probe terminals from conducting each other even if the pitch of the probe terminals and thus the pitch of the first terminals are reduced.
[0017]
In the inspection substrate according to the present invention, it is preferable that the corresponding substrate electrode and the second terminal among the plurality of substrate electrodes and the plurality of second terminals face each other.
[0018]
This simplifies the structure of the conductor that electrically connects the substrate electrode and the second terminal.
[0019]
The inspection substrate according to the present invention preferably includes a wiring layer provided on the second main surface of the flexible substrate and connecting the corresponding first terminal and second terminal.
[0020]
In this case, the first terminal and the second terminal can be easily and reliably connected.
[0021]
In the inspection board according to the present invention, the corresponding first terminal and second terminal may be connected by a bonding wire.
[0022]
In the inspection board according to the present invention, the height of the elastic body is preferably equal to or larger than the height of the conductor.
[0023]
In this way, even if a step is generated between the test electrodes on the semiconductor wafer or between the probe terminals on the flexible substrate, the test electrodes and the probe terminals can be reliably brought into contact with the entire surface of the semiconductor wafer. it can.
[0024]
The inspection board according to the present invention preferably includes an insulating sheet member provided between the wiring board and the flexible board and holding a plurality of conductors and a plurality of elastic bodies.
[0025]
This facilitates providing a plurality of conductors and elastic bodies between the wiring board and the flexible board.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, an inspection substrate according to a first embodiment of the present invention will be described with reference to FIG.
[0027]
As shown in FIG. 1, a semiconductor wafer 12 on which a plurality of semiconductor chips are formed is held on a wafer tray 11 as in the prior art, and a plurality of inspection wafers are provided on a main surface (upper surface) of the semiconductor wafer 12. An electrode 12a is formed.
[0028]
A wiring board 21 is arranged above the semiconductor wafer 12, and a lower wiring 21 a, an upper wiring 21 b, and a substrate electrode 21 c are formed on a surface (lower surface) of the wiring substrate 21 facing the main surface of the semiconductor wafer 12. The substrate electrode 21c is connected to the lower wiring 21a, and the substrate electrodes 21c are connected to each other by the upper wiring 21b.
[0029]
A flexible board 22 is arranged between the semiconductor wafer 12 and the wiring board 21 so as to be spaced from the wiring board 21. A plurality of probe terminals 22a made of bumps are formed on a portion of the first main surface (lower surface) of the flexible substrate 22 facing the semiconductor wafer 12 and facing the inspection electrode 12a. Further, on the second main surface (upper surface) of the flexible substrate 22 opposite to the wiring substrate 22, a portion opposite to each probe terminal 22 a (a portion facing each probe terminal 22 a) is electrically connected to the corresponding probe terminal 22 a. A plurality of first terminals 22b which are electrically connected to each other, and a second terminal 22c is formed on a portion of the second main surface of the flexible substrate 22 different from the first terminals 22b; The first terminal 22b and the second terminal 22c are electrically connected by a lead wiring 22d.
[0030]
An insulating sheet member 23 made of, for example, rubber is disposed between the flexible board 22 and the wiring board 21. A conductor 23a made of, for example, gold is fitted in a portion of the insulating sheet member 23 facing the second terminal 22b of the flexible board 22, and the board electrode 21c of the wiring board 21 and the second Terminal 22b is electrically connected to conductor 22a. Further, a protruding portion 23b is formed in a portion of the insulating sheet member 23 facing the first terminal 22b of the flexible board 22, and when a pressing force for bringing the wiring board 21 and the flexible board 22 close to each other is applied, the flexible board 22 becomes flexible. Since the probe terminal 22a of the substrate 22 is pressed toward the inspection electrode 12a of the semiconductor wafer 12 by the elastic force of the protruding portion 23b, even if the semiconductor wafer 12 has a step or warp, Reliable contact between the probe terminal 22a and the inspection electrode 12a can be secured over the entire surface of the semiconductor wafer 12.
[0031]
According to the first embodiment, the protruding portion 23b made of an elastic body that absorbs the step of the probe terminal 22a and the conductor 23a that electrically connects the substrate electrode 21c and the second terminal 22c are provided at different positions. Therefore, even if the pressing force for bringing them close to the wiring board 21 and the flexible board 22 repeatedly acts on the wiring board 21 and the flexible board 22, and the protrusion 23 b is deformed or the elastic force of the protrusion 23 b is deteriorated, The resistance value between the substrate electrode 21c of the substrate 21 and the second terminal 22c of the flexible substrate 22 does not increase.
[0032]
In the first embodiment, the entire height of the protrusion 23b is equal to the height of the conductor 23a or larger than the height of the conductor 23a. Therefore, even if a step is generated between the test electrodes 12a of the semiconductor wafer 12 or between the probe terminals 22a of the flexible substrate 22, the test electrodes 12a and the probe terminals 22a are securely formed on the entire surface of the semiconductor wafer 12. Can be contacted.
[0033]
Further, according to the first embodiment, the second terminal 22b electrically connected to the substrate electrode 21c is provided at a position different from the first terminal 22a provided at a portion facing the probe terminal 22a. Therefore, the pitch of the second terminals 22b can be made larger than the pitch of the first terminals 22a. Therefore, even if the pitch of the probe terminals 22a and thus the pitch of the first terminals 22a becomes smaller, the adjacent probe terminals 22a It is possible to prevent conduction between them.
[0034]
In the first embodiment, the structure of the conductor 23a is simplified because the substrate electrode 21c and the second terminal 22c face each other, but the substrate electrode 21c and the second terminal 22c are It does not have to face each other.
[0035]
In the first embodiment, since the conductor 23 a and the protruding portion 23 b are provided on the insulating sheet member 23, the conductor 23 a and the elastic body can be easily and simply provided between the wiring board 21 and the flexible board 22. It can be arranged reliably.
[0036]
(Second embodiment)
Hereinafter, an inspection substrate according to a second embodiment of the present invention will be described with reference to FIG.
[0037]
As shown in FIG. 2, a semiconductor wafer 12 on which a plurality of semiconductor chips are formed is held on a wafer tray 11 as in the conventional case, and a plurality of inspection wafers are provided on a main surface (upper surface) of the semiconductor wafer 12. An electrode 12a is formed.
[0038]
A wiring substrate 31 is arranged above the semiconductor wafer 12, and a lower wiring 31 a, an upper wiring 31 b and a substrate electrode 31 c are formed on a surface (lower surface) of the wiring substrate 31 facing the main surface of the semiconductor wafer 12. The substrate electrode 31c is connected to the lower wiring 31a, and the substrate electrodes 31c are connected to each other by the upper wiring 31b.
[0039]
A flexible board 32 is arranged between the semiconductor wafer 12 and the wiring board 31 so as to be spaced from the wiring board 31. A plurality of probe terminals 32a formed of bumps are formed on a portion of the first main surface (lower surface) of the flexible substrate 32 facing the semiconductor wafer 12 and facing the inspection electrode 12a. Further, on the second main surface (upper surface) of the flexible substrate 32 facing the wiring board 32, a portion opposite to each probe terminal 32a (a portion facing each probe terminal 32a) is electrically connected to the corresponding probe terminal 32a. A plurality of first terminals 32b which are electrically connected to each other, and a second terminal 32c is formed in a portion of the second main surface of the flexible substrate 32 different from the first terminals 32b, The first terminal 32b and the second terminal 32c are electrically connected by a bonding wire 32d.
[0040]
An insulating sheet member 33 made of, for example, rubber is disposed between the flexible board 32 and the wiring board 31, and a portion of the insulating sheet member 33 facing the first terminal 32 b of the flexible board 32 protrudes. A portion 33b is formed. When a pressure is applied to bring the wiring board 31 and the flexible board 32 closer to each other, the probe terminals 32a of the flexible board 32 are pressed toward the inspection electrodes 12a of the semiconductor wafer 12 by the elastic force of the protrusions 33b. Even if a step is present or warpage occurs in the semiconductor wafer 12, reliable contact between the probe terminal 32 a and the inspection electrode 12 a can be secured over the entire surface of the semiconductor wafer 12.
[0041]
A conductor 34 made of, for example, a gold bump is provided on the substrate electrode 31 c of the wiring substrate 31. The conductor 34 electrically connects the substrate electrode 31 c of the wiring substrate 31 and the second terminal 32 b of the flexible substrate 32. It is connected.
[0042]
According to the second embodiment, the protruding portion 33b made of an elastic body that absorbs the step of the probe terminal 32a and the conductor 34 that electrically connects the substrate electrode 31c and the second terminal 32c are provided at different positions. Therefore, even if the pressing force for bringing them close to the wiring board 31 and the flexible board 32 acts repeatedly, and the protrusion 33b is deformed or the elastic force of the protrusion 33b is deteriorated, the wiring board The resistance value between the substrate electrode 31c of the first substrate 31 and the second terminal 32c of the flexible substrate 32 does not increase.
[0043]
In the second embodiment, the entire height of the protrusion 33b is equal to or larger than the height of the conductor 34. Therefore, the inspection electrode 12a and the probe terminal 32a can be reliably brought into contact with each other over the entire surface of the semiconductor wafer 12.
[0044]
Further, according to the second embodiment, the second terminal 32b electrically connected to the substrate electrode 31c is provided at a position different from the first terminal 32a provided at a portion facing the probe terminal 32a. Therefore, the pitch of the second terminals 32b can be made larger than the pitch of the first terminals 32a. Therefore, even if the pitch of the probe terminals 32a and thus the pitch of the first terminals 32a become smaller, the adjacent probe terminals 32a It is possible to prevent conduction between them.
[0045]
【The invention's effect】
According to the inspection board according to the present invention, even if the pressing force for causing the wiring board and the flexible board to approach each other repeatedly acts, the resistance value between the board electrode of the wiring board and the second terminal of the flexible board is increased. Does not increase, and even if the pitch of the probe terminals is reduced, it is possible to prevent the adjacent probe terminals from conducting.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an inspection substrate according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of an inspection substrate according to a second embodiment of the present invention.
FIG. 3 is a cross-sectional view of a conventional inspection substrate.
[Explanation of symbols]
Reference Signs List 11 Wafer tray 12 Semiconductor wafer 12a Inspection electrode 21 Wiring board 21a Lower wiring 21b Upper wiring 21c Substrate electrode 22 Flexible substrate 22a Probe terminal 22b First terminal 22c Second terminal 22d Lead wiring 23 Insulating sheet member 23a Conductor 23b Projection Part 31 wiring board 31a lower layer wiring 31b upper layer wiring 31c board electrode 32 flexible substrate 32a probe terminal 32b first terminal 32c second terminal 32d bonding wire 33 insulating sheet member 33b protrusion 34 conductor

Claims (6)

A test substrate for applying a voltage to a plurality of test electrodes of a plurality of semiconductor chips formed on a semiconductor wafer to collectively test the electrical characteristics of the plurality of semiconductor chips at a wafer level,
A wiring substrate having a plurality of substrate electrodes on a surface of the semiconductor wafer facing a main surface on which the plurality of inspection electrodes are formed,
A first main surface, which is provided between the semiconductor wafer and the wiring substrate and at a distance from the wiring substrate and faces the main surface of the semiconductor wafer, and the substrate electrodes of the wiring substrate are formed; A flexible substrate having a second main surface facing the surface being
A plurality of probe terminals provided on a portion of the first main surface of the flexible substrate facing the plurality of test electrodes;
A plurality of first terminals which are provided at a portion of the second main surface of the flexible substrate facing the plurality of probe terminals and are electrically connected to the opposed probe terminals;
A plurality of second terminals that are provided at different portions of the second main surface of the flexible substrate from the plurality of first terminals and are electrically connected to the corresponding first terminals;
A plurality of conductive members provided between the wiring substrate and the flexible substrate and electrically connecting the corresponding substrate electrode and the second terminal among the plurality of substrate electrodes and the plurality of second terminals. Body and
An inspection board, comprising: a plurality of elastic bodies provided between the wiring board and the flexible board at locations facing the plurality of first terminals. The inspection substrate according to claim 1, wherein the substrate electrode and the second terminal corresponding to the plurality of substrate electrodes and the plurality of second terminals are opposed to each other. 2. The inspection device according to claim 1, further comprising a wiring layer provided on the second main surface of the flexible substrate and connecting the corresponding first terminal and the second terminal. 3. substrate. The inspection substrate according to claim 1, further comprising a bonding wire that connects the corresponding first terminal and the second terminal. The inspection substrate according to claim 1, wherein the height of the elastic body is equal to or higher than the height of the conductor. The inspection according to claim 1, further comprising an insulating sheet member provided between the wiring board and the flexible board and holding the plurality of conductors and the plurality of elastic bodies. Substrate.

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